UK Statistics Authority boss David Norgrove strongly criticised the foreign secretary for repeating the dubious claim that Britain would be able to spend an extra £350 million a week on the NHS once it had left the EU,.

Scottish Tory leader Ruth Davidson made a coded attack on Johnson for striking out in the Daily Telegraph as London suffered another terrorist attack.

And home secretary Amber Rudd accused her colleague of "backseat driving" in the Brexit process.

But Johnson’s allies admitted that the article would help him position himself for the job. “It certainly won’t do him any harm,” one said.

And now comes evidence that the foreign secretary’s pals may have been right.

Their man is now the top choice among Conservative party members to replace Theresa May as prime minister, according to a new poll.

The YouGov survey for The Times shows that Johnson now has the backing of 23% of activists.

He is ahead of the unlikely candidates Ruth Davidson on 19% and Jacob Rees-Mogg on 17%. Davidson cannot be Tory leader until she gets a seat in the Commons while Rees Mogg would struggle because he does not have support among Tory MPs.

David Davis, who does have parliamentary backers and is known to be keen on getting the top job, comes fourth with 11% - suggesting Johnson would easily beat him if there were a contest between the pair.

The favoured candidate of many liberal Tory MPs and opponents of a hard Brexit, Amber Rudd, is in fifth - with just 6% of the party faithful behind her.